Proposed Biles-Coleman Lumber Co 2-6-6-2 "Mallet Mogul" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 8043 (Locobase 10694)

Data from [], last accessed 26 July 2009. See also John E Lewis, Biles-Coleman Lumber Company's Reservation Narrow Gauge (Washington State: privately printed First Edition of 2,500 copies, 1980). (Many thanks to Ken Matzick for his 5 July 2015 email correcting the over-long stroke Locobase had originally entered.)

This locomotive was never actually built. B-C Lumber of Omak, Washington asked for a proposal from Baldwin and this is what the company submitted. It was based on the Ferrocarril do Sur #9 of 1921, described in Locobase 4762. Interestingly, this was not the heaviest 3-footer; several designs were built that were heavier.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID10,694
RailroadProposed Biles-Coleman Lumber Co
Number in Class
Road Numbers
Number Built
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)7 / 2.13
Engine Wheelbase (ft / m)20.75 / 6.32
Ratio of driving wheelbase to overall engine wheebase 0.34
Overall Wheelbase (engine & tender) (ft / m)33.67 / 10.26
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)115,000 / 52,163
Engine Weight (lbs / kg)180,000 / 81,647
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)180,000
Tender Water Capacity (gals / ML)1500 / 5.68
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)700 / 2.70
Minimum weight of rail (calculated) (lb/yd / kg/m)32 / 16
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)38 / 965
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)13.5" x 20" / 343x508
Low Pressure Cylinders (dia x stroke) (in / mm)21" x 20" / 533x508
Tractive Effort (lbs / kg)23,076 / 10467.11
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.98
Heating Ability
Firebox Area (sq ft / m2)70 / 6.50
Grate Area (sq ft / m2)11.70 / 1.09
Evaporative Heating Surface (sq ft / m2)712 / 66.15
Superheating Surface (sq ft / m2)143 / 13.29
Combined Heating Surface (sq ft / m2)855 / 79.44
Evaporative Heating Surface/Cylinder Volume214.89
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2340
Same as above plus superheater percentage2738
Same as above but substitute firebox area for grate area16,380
Power L13711
Power MT426.85

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Wes Barris